/*
 * EAP peer method: EAP-OTP (RFC 3748)
 * Copyright (c) 2004-2006, Jouni Malinen <j@w1.fi>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Alternatively, this software may be distributed under the terms of BSD
 * license.
 *
 * See README and COPYING for more details.
 */

#include "includes.h"

#include "common.h"
#include "eap_i.h"


static void * eap_otp_init(struct eap_sm *sm)
{
        /* No need for private data. However, must return non-NULL to indicate
         * success. */
        return (void *) 1;
}


static void eap_otp_deinit(struct eap_sm *sm, void *priv)
{
}


static struct wpabuf * eap_otp_process(struct eap_sm *sm, void *priv,
                                       struct eap_method_ret *ret,
                                       const struct wpabuf *reqData)
{
        struct wpabuf *resp;
        const u8 *pos, *password;
        size_t password_len, len;
        int otp;

        pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_OTP, reqData, &len);
        if (pos == NULL) {
                ret->ignore = TRUE;
                return NULL;
        }
        wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-OTP: Request message",
                          pos, len);

        password = eap_get_config_otp(sm, &password_len);
        if (password)
                otp = 1;
        else {
                password = eap_get_config_password(sm, &password_len);
                otp = 0;
        }

        if (password == NULL) {
                wpa_printf(MSG_INFO, "EAP-OTP: Password not configured");
                eap_sm_request_otp(sm, (const char *) pos, len);
                ret->ignore = TRUE;
                return NULL;
        }

        ret->ignore = FALSE;

        ret->methodState = METHOD_DONE;
        ret->decision = DECISION_COND_SUCC;
        ret->allowNotifications = FALSE;

        resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_OTP, password_len,
                             EAP_CODE_RESPONSE, eap_get_id(reqData));
        if (resp == NULL)
                return NULL;
        wpabuf_put_data(resp, password, password_len);
        wpa_hexdump_ascii_key(MSG_MSGDUMP, "EAP-OTP: Response",
                              password, password_len);

        if (otp) {
                wpa_printf(MSG_DEBUG, "EAP-OTP: Forgetting used password");
                eap_clear_config_otp(sm);
        }

        return resp;
}


int eap_peer_otp_register(void)
{
        struct eap_method *eap;
        int ret;

        eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
                                    EAP_VENDOR_IETF, EAP_TYPE_OTP, "OTP");
        if (eap == NULL)
                return -1;

        eap->init = eap_otp_init;
        eap->deinit = eap_otp_deinit;
        eap->process = eap_otp_process;

        ret = eap_peer_method_register(eap);
        if (ret)
                eap_peer_method_free(eap);
        return ret;
}
